The goal of the Pathology Core is to provide service, expertise and professional consultation to all Investigators of the Cystic Fibrosis PPG. To facilitate these goals the Pathology Core will provide 1) technical assistance for labor intensive histotechnology techniques from tissue processing to specialized staining, 2) professional veterinary pathology support for gross, microscopic and anatomic phenotyping of the CFTR-/-pig model, 3) economic benefits through centralization of equipment, experienced staff and availability of specialized reagents, and 4) consultation and instruction in specialized morphologic techniques and image analysis. Program Investigators will have full access to the Core's expertise and resources. The Pathology Core will provide its services to Program Investigators in a timely and efficient manner for optimal assessment of tissues. The Specific Aims of the Pathology Core are: 1) Provide scientific support, expertise and technical labor for microscopic slide processing from tissues, routine to specialized application of tinctorial stains, and immunohistochemistry techniques. 2) Provide expertise and resources to develop new morphologic or morphmetric techniques as required to facilitate the needs of Project Investigators. 3) Provide veterinary pathology support (though boarded veterinary pathologists) for examination and interpretation of gross to microscopic tissues from the CFTR-/- pig and for consultation in experimental design. 4) Provide expertise and a uniform framework for the standardized assessment of tissues collected by Project Investigators to define a comprehensive anatomic phenotype of the novel porcine CFTR-/- model.